Lester T. Toy - San Francisco CA Wendell W. Moyer - Atherton CA Bernard J. Lyons - Atherton CA David A. Horsma - Palo Alto CA
Assignee:
Raychem Corporation - Menlo Park CA
International Classification:
H01B 104 H01C 713
US Classification:
338 22SD
Abstract:
Conductive polymer compositions which have improved voltage stability and which preferably exhibit PTC behavior. The compositions comprise a carbon black dispersed in a crystalline copolymer of an olefin and at least 10% by weight of an olefinically unsaturated comonomer containing a polar group. The carbon black has a particle size greater than 18 millimicrons, preferably greater than 30 millimicrons, a d-spacing greater than 360 and a surface area which is less than 1. 2S+e. sup. S/50 where S is the DBP absorption of the carbon black. The carbon black is preferably present in amount at least 15% by weight of the composition. Particularly useful devices including such compositions are self-regulating heaters.
Rong J. Chang - Fremont CA John A. Midgley - San Carlos CA Lester T. Toy - Fremont CA
Assignee:
Raychem Corporation - Menlo Park CA
International Classification:
H02G 1508 H02G 114
US Classification:
174 77R
Abstract:
The invention relates to a sealed cable article and method for sealing the area between two or more cables and between the cables and an enclosure with a shaped article at a location where the cables exit from the enclosure, the method comprising (a) providing a shaped article of a polymeric gel said gel having (i) a cone penetration value of about 30 to about 450 (10. sup. -1 mm), and (ii) an elongation of from about 25% to about 750%; (b) positioning the shaped article around the cables; and (c) positioning the enclosure such that it surrounds the shaped article. An article aspect of the invention comprises two or more cables, an enclosure surrounding the cables, and a polymeric gel having the properties as described above sealing the area between the cables and the enclosure. This invention also relates to a sealed cable end article and a method of sealing the end of a cable, the method comprising positioning a shaped article of a polymeric gel having the properties as described above to cover the end of a cable and positioning an enclosure around said shaped article and adjacent region of the cable. The article comprises one or more cable ends with a portion of the cable end exposed, a shaped article of a polymeric gel having the properties as described above positioned at the cable end, and an enclosure which surrounds the shaped article and the adjacent region of the cable.
A process for manufacturing a sealant coated heat recoverable polymeric article is disclosed. The process includes the steps of extruding at least two different polymeric materials to form a unitary shaped article and thereafter exposing the shaped article to a source of ionizing radiation to thereby cross-link one of the polymeric materials and convert the other polymeric material into a tacky sealant. The article may be rendered dimensionally heat recoverable by either: (a) deforming the article into a different shape at a temperature below the crystalline melt temperature of the cross-linkable material and then exposing the deformed article to a source of ionizing radiation or alternatively, (b) subsequent to an irradiation step, heating the article to about the crystalline melt temperature of the cross-linked material, distorting the article, and then cooling the article while maintaining it in the distorted shape to a temperature below the crystalline melt temperature; thereby by either method rendering the cross-linked portion of the article recoverable toward its original shape upon subsequent heating.
Willem M. Versteegh - Fremont CA Lester T. Toy - Fremont CA Christine Holland - San Mateo CA
International Classification:
F16L 914
US Classification:
428 36
Abstract:
A heat recoverable tubular composite article comprising an inner layer comprising a crosslinked elastomeric polymeric material having a modulus at 100% elongation at 20. degree. C. of about 40 to about 900 pounds per square inch and an outer layer comprising a thermoplastic material having a 2% secant modulus at 20. degree. C. of about 5,000 to about 100,000 pounds per square inch said composite article (1) being formed by coextrusion, (2) having a direct bond between said layers with a peel strength of at least 6 pounds per linear inch, and (3) being in a radically expanded configuration, said thermoplastic outer layer being capable of retaining the elastomeric inner layer in an expanded configuration at ambient temperature and incapable of retaining the elastomeric layer in an expanded configuration at a temperature above a predetermined temperature thereby permitting the composite article to recover to or toward its unexpanded configuration.
Lester T. Toy - Fremont CA Daniel Magay - Los Altos CA
Assignee:
Raychem Corporation - Menlo Park CA
International Classification:
H01R 402
US Classification:
439874
Abstract:
A heat activatable sealing piston comprising a cylinder of polymeric material radially expandable on application of heat. The piston can be incorporated into thermal actuators of various types. In a preferred embodiment, the sealing piston is used in an electrical connector, together with a gas generating means to force solder between an electrical conductor inserted into the connector and the walls of the tubular connector.
Insulating Multiple-Conductor Cables Using Coated Insert Means
Manoochehr Mohebban - Belmont CA Willem M. Versteegh - Fremont CA Lester T. Toy - Fremont CA
Assignee:
Raychem Corporation - Menlo Park CA
International Classification:
H01B 1322
US Classification:
156 49
Abstract:
The conductors of multi-conductor, medium voltage, power cables, at locations where the cable insulation has been removed, are insulated by positioning between the conductors or cores, an insert, at least the surface of which comprises a first void-filling material capable of forming a substantially void-free interface with each conductor, placing a second void-filling material over the conductors and recovering a dimensionally recoverable polymeric sleeve over the resulting assembly. The method is particularly useful to provide insulation between conductors of a joint between two multi-conductor, medium voltage power cables.
A substantially solvent-free adhesive composition consists essentially of an elastomer and tackifier, a metal oxide and, optionally, a plasticizer. The elastomer is selected from the group consisting of polar elastomers and unsaturated elastomers which have at least 5 mole percent unsaturation, said elastomer being a non-crystalline elastomer or an elastomer which has a slow rate of crystallization such that after a time period of at least 100 hours has elapsed following subjecting the elastomer to a temperature of 70. degree. C. for 30 minutes, the elastomer has a room temperature Shore A hardness of less than 60. The adhesive compositions can be formed into a shaped article, such as of a tape, film, sheet or tubular sleeve, if desired. The compositions have high adhesive strength for bonding together a variety of substrates. The adhesive is particularly useful with a dimensionally recoverable article, such as a shrinkable sleeve, to bond the recovered sleeve to a substrate such as an electric cable.
The invention relates to an article for sealing the exposed portion an electrical connection, especially motor connections, of two or more cables comprising an envelope, having an opening at one end, of a material having a flexural modulus of at least 1,000 psi at 23. degree. C. The envelope contains a polymeric gel having a cone penetration value of about 30 to about 400 (10. sup. -1 mm) and an elongation of from about 25% to about 850% and further comprises a retaining means for retaining the polymeric gel and envelope on the electrical connection.